Camera and 3D¶

The camera decides what the video shows. Its frame is a rectangle in the scene: the frame that Positions measures. Move the frame, and the view moves with it.

Pan and zoom¶

self.camera.frame is a mobject. Animate it as any other mobject:

import manimgx as m


class Zoom(m.Scene):
    def construct(self) -> None:
        circle = m.Circle(radius=3, color=m.BLUE)
        tangent = m.Line(4 * m.LEFT, 4 * m.RIGHT, color=m.YELLOW)
        tangent.shift(3 * m.UP)
        self.add(circle, tangent)
        frame = self.camera.frame
        self.play(frame.animate.scale(0.25).move_to(3 * m.UP), run_time=2)
        self.wait()
        self.play(frame.animate.scale(4).move_to(m.ORIGIN), run_time=2)

Move the frame to pan: frame.animate.move_to(point).
Scale it to zoom: a frame half as large shows everything twice as large.

Three dimensions¶

To make a scene in 3D, make it from m.ThreeDScene. Its camera looks at the frame from two angles:

phi, its angle from straight above: 0 looks straight down, as in a flat scene.
theta, its angle around the vertical axis.

import manimgx as m
import numpy as np


class Hill(m.ThreeDScene):
    def construct(self) -> None:
        axes = m.ThreeDAxes(
            x_range=[-3, 3],
            y_range=[-3, 3],
            z_range=[0, 2],
            x_length=7,
            y_length=7,
            z_length=3,
        )

        def height(u: float, v: float) -> np.ndarray:
            return axes.c2p(u, v, 2 * np.exp(-(u**2 + v**2) / 2))

        hill = m.Surface(height, u_range=[-2.5, 2.5], v_range=[-2.5, 2.5])
        title = m.Text("A hill", font_size=40)
        title.to_corner(m.UL)
        self.add_fixed_in_frame_mobjects(title)
        self.add(axes, hill)
        self.move_camera(phi=65 * m.DEGREES, theta=-45 * m.DEGREES, run_time=2)
        self.begin_ambient_camera_rotation(rate=0.3)
        self.wait(3)

self.set_camera_orientation(phi=..., theta=...) turns the camera at once, and self.move_camera(...) turns it in an animation.
self.begin_ambient_camera_rotation(rate=0.3) turns the camera around the scene, until self.stop_ambient_camera_rotation().
self.add_fixed_in_frame_mobjects(title) keeps a mobject still on the screen while the camera moves: here, the title stays in its corner.

Every mobject has three coordinates, so flat mobjects work in 3D too. The reference shows the mobjects made for 3D, such as spheres and cubes.

Next¶

Sound and voice shows how to add sound and a voice to your video.